Protesters, who first called for reforms and greater freedoms, have hardened their demands with many chanting for the overthrow of President Bashar Assad.
Wednesday was one of the bloodiest days apart from the main Friday protest days, when thousands use the platform of weekly Muslim prayers to demonstrate. Most of the violence occurred in the southern Deraa province, where unrest erupted on March 18.
Ammar Qurabi, head of the National Organization for Human Rights in Syria, said 13 people were killed in the town of Harra, about 60 km northwest of Deraa city.
Most were killed when tanks shelled four houses. Two people — a child and a nurse — died in gunfire, he said.
Tanks also shelled a residential district in Homs, Syria’s third largest city, and at least five people were killed, a rights campaigner in the city said. A sixth person was killed by a sniper shot to the head as he stood in front of his house.
“The security forces are terrorizing urban centers,” said Najati Tayara, the activist in Homs.
There was no immediate comment from Syrian authorities, who have banned most international media from Syria, making it difficult to verify accounts of events.
The violence has been denounced in the West, where countries have imposed limited sanctions on Syrian leaders but stopped short of calling for Assad to step down.
Syria withdrew its candidacy on Wednesday for a spot on the top UN human rights body. Its ambassador to the United Nations, Bashar Jaafari, said Damascus was “reconsidering our priorities” and would try again in 2013.
US Ambassador Susan Rice said Syria’s bid was blocked by Asian states with the “good sense” to withhold support for a country “in the process of killing its own people on the streets, arresting thousands and terrorizing a population that is seeking to express itself through largely peaceful means.”
In Damascus, security forces have arrested opposition leader Mazen Adi, from the People’s Democratic Party founded by Syria’s top dissident, Riad Al-Turk, according to rights activists.
They added that thousands of pro-democracy Syrians had been arrested and beaten in the last two months, including scores on Wednesday in Homs and in the coastal city of Banias.
A cousin of the president said the Assad family was not going to capitulate. “We will sit here. We call it a fight until the end ... They should know when we suffer, we will not suffer alone,” Rami Makhlouf told the New York Times.
Makhlouf, a tycoon in his early 40s, and his brother, a secret police chief, have been under US sanctions since 2007.
Demonstrators have shouted the name of Makhlouf as a symbol of corruption in a country that has faced severe water shortages and unemployment.
In Banias, protesters held up pictures of Turkish Prime Minister Tayyip Erdogan to salute him for his stand against what they perceive as Assad’s iron fist policy toward opposition.
Erdogan maintains close trade and diplomatic ties with Assad but has disputed the official Damascus account of the violence.
Erdogan said more than 1,000 civilians had died in Syria’s upheaval. He said he did not want to see a repeat of the 1982 bloodshed in Hama or the 1988 gassing of Kurds in the Iraqi town of Halabja.
In Geneva, UN Secretary-General Ban Ki-moon urged Syria to halt mass arrests and to heed calls for reform. Ban also said that UN humanitarian workers and human rights monitors must be allowed into Deraa as well as other cities.
